Old China, I do not use a travel agent. I use the Cathay web site. The business fare MNL/BKK/HKG/MNL went from about 900 to USD 3000 MNL/SGN/HKG/MNL from USD 900 USD 3700 one time and USD 4500 another when I included a 10 day stopover in Hong Kong. Try it yourself. I was told by a Cathay employee that they are experimenting with new fare calculations. Perhaps they are restricting the length of the stopover as suggested above. I shall search using a shorter stopover.